As the Atlantic hurricane season continues, contractors who built the solar farm in Bodden Town that opened in June say hurricane force winds are unlikely to lift any of the nearly 22,000 panels off their foundations.
Each of the 21,690 panels on the 22-acre former vegetable farm near Pease Bay Pond weighs 40 pounds, but, according to Neil Armstrong, owner of contractor Clan Construction, “they are not going to lift up off the ground. The frames will never lift and the ballast will hold. It’s anchored with a yard-and-a-half of concrete.
“All of that, together with the rails, was one of the first questions we asked when we designed this,” he said.
The narrow “rails” run in parallel beneath the panels, linking and securing them, particularly on slanted surfaces, as part of the mounting structure.
Armstrong said bolts had been tightened and screws driven, preventing storm-driven winds from lifting the panels off their mounts.
“We had independent engineers come down from the U.S. to check,” he said.
Mr. Armstrong’s Clan Construction started work on the $4 million, 5 megawatt Bodden Town array in late February, completing the project in April. Farm owner Entropy Investment Management and the Caribbean Utilities Company opened the power plant on June 20.
James Whittaker, owner and founder of local solar designer and installer Greentech, and chairman of the Cayman Islands Renewable Energy Association, worried about flooding, however.
“There’s not much more you can do than what’s already there to secure the solar farm. The weakness I see in the Bodden Town design is the tubs that sit on grade. [They are] very cost effective, but that land is soft and if/when it floods and [the] ground below turns to mud, the arrays will shift and the glass on the panels will start to shatter,” he said.
“Or so I suspect. Hopefully not, but we’ll see.”
Mr. Armstrong quickly sought to allay concerns, however: “The ground was demucked, and crushed rock was placed on the surface by the land owner.
“The ballasts are held down with concrete foundations. The only way these ballasts would move would need to involve a tsunami.” During construction, the company added four feet to the height of the property, further ensuring against flood-related shifting. Mr. Armstrong acknowledged early concerns about hurricane winds lifting the panels, “but it’s engineered to withstand this.”
Design and licensing specifications for the farm require loading to withstand 155 mile per hour winds.
The crushed rock beneath the concrete ballast is likely to stop mud from forming, while any shifting beneath the substrate will be countered by the steel superstructure holding the concrete in position.
On Wednesday, weekly Cleveland-based industry newsletter Solar Power World detailed what it called “the solar industry’s best warranty,” minimizing storm worries with a 25-year guarantee in the face of “extreme weather, wide-ranging temperatures [and] panel aging.”